Moxie and only Moxie

SpaceNut · 2021-10-19 17:49:49

A ratio of 30 seems to be where we are for the "axial compressor" atmospheric pressure on the Martian surface averages 600 pascals (0.087 psi) means 18,000 pascals (2.61 psi) so its got to be compressed more.
Nice touch to couple the Stirling shaft for rotation.

SpaceNut · 2022-03-12 18:28:29

4-21-21 NASA’s Perseverance Mars Rover Extracts First Oxygen from Red Planet

o burn its fuel, a rocket must have more oxygen by weight. Getting four astronauts off the Martian surface on a future mission would require approximately 15,000 pounds (7 metric tons) of rocket fuel and 55,000 pounds (25 metric tons) of oxygen. In contrast, astronauts living and working on Mars would require far less oxygen to breathe. “The astronauts who spend a year on the surface will maybe use one metric ton between them,” Hecht said.
Hauling 25 metric tons of oxygen from Earth to Mars would be an arduous task. Transporting a one-ton oxygen converter – a larger, more powerful descendant of MOXIE that could produce those 25 tons – would be far more economical and practical.
Mars’ atmosphere is 96% carbon dioxide. MOXIE works by separating oxygen atoms from carbon dioxide molecules, which are made up of one carbon atom and two oxygen atoms. A waste product, carbon monoxide, is emitted into the Martian atmosphere.
The conversion process requires high levels of heat to reach a temperature of approximately 1,470 degrees Fahrenheit (800 Celsius). To accommodate this, the MOXIE unit is made with heat-tolerant materials. These include 3D-printed nickel alloy parts, which heat and cool the gases flowing through it, and a lightweight aerogel that helps hold in the heat. A thin gold coating on the outside of MOXIE reflects infrared heat, keeping it from radiating outward and potentially damaging other parts of Perseverance.
In this first operation, MOXIE’s oxygen production was quite modest – about 5 grams, equivalent to about 10 minutes worth of breathable oxygen for an astronaut. MOXIE is designed to generate up to 10 grams of oxygen per hour.

seems that the design is way off if all that was made is 5.4 grams of oxygen in one hour and if that is roughly 10 minutes of breathable air for a human being. so we need 6 of these operating 24/7 to even break even for requirement for a person.

first_operations_-_moxie_oxygen_production.jpg?itok=2ismmrWd

Calliban · 2022-04-20 05:51:41

The link below is for a commercial CO2 electrolysis unit, producing CO and O2.
https://www.topsoe.com/processes/carbon-monoxide

I was considering the possibility of using compressed CO/O2 as a bipropellant combination for a pressure fed rocket sled on Mars. If we can do this, we can manufacture interplanetary ships on Mars surface and launch them in a way that would never be possible on Earth. The thin atmosphere would allow bulky objects to be launched by rocket sled without too much problem from air resistance. The dV required to get from Mars surface to LMO is about 4km/s. If the rocket sled can accelerate the payload to 2-3km/s, then a minimal upper stage or the ships own propulsion system, can provide the remainder of dV needed to reach orbital velocity.

On Mars, we could feed a solid oxide electrolysis cell with liquid CO2 at a feed pressure of 200 bar. The CO/O2 gas stream emerging from the electrolysis unit would then have sufficient discharge pressure to feed the propellant tanks directly, without compression.

The propellant tanks would need high strength to weight ratio to make use of compressed gas fuels and still retain sufficiently high mass ratio at a burn out velocity of 2.5km/s. A basalt fibre wound carbon steel tank looks promising.

Last edited by Calliban (2022-04-20 06:09:02)

tahanson43206 · 2022-04-20 06:12:50

For Calliban re #53

In the context of Mars, good ideas in one specialization can be helpful in others.

Your description of a CO/O2 propulsion capability based upon an electrolysis unit matches up nicely with another topic in the forum. That one was (and is) dedicated to development of CO/O2 based tools and reciprocating engines for construction and manufacturing on Mars.

SearchTerm:CO/O2 infrastructure on Mars

This topic is presumably about a system to produce oxygen on Mars.

Since I have forgotten what the topic was about, here is a snippet from Google:

The Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) is a technology demonstration on the NASA Mars 2020 rover Perseverance investigating the production of oxygen on Mars. On April 20, 2021, MOXIE produced oxygen from carbon dioxide in the Martian atmosphere by using solid oxide electrolysis.
Mars Oxygen ISRU Experiment - Wikipedia
en.wikipedia.org › wiki › Mars_Oxygen_ISRU_Experiment
About Featured Snippets

So! The natural evolution of this discussion would be a comparison of the NASA experiment and the commercial system reported in Post #53

(th)

SpaceNut · 2022-04-20 17:39:30

yes co is an exhaust that after you have expended power should not be expelled back into the atmosphere only to require more power to recapture it for another purpose. This is where we get into complete process use so as to make a more encompassing use of the energy which if solar can not be wasted in any watt level.....
Yes there is a co/o2 fuel rocket topic.

SpaceNut · 2022-08-31 20:22:26

The triple point is a frost, and it takes quite a bit before the temperature and pressure will make it liquid.
The current device uses a scroll compressor that pushes the CO2 into the high temperature electrolysis plates with catalyst.

NASA made enough oxygen on Mars to last an astronaut for 100 minutes
worth of breathable oxygen in 2021...

Over the course of seven hour-long production runs during that year, MOXIE was able to reliably produce roughly 15 minutes of oxygen per hour in a variety of harsh planetary conditions. That added up to a total of 50 grams of oxygen in total

7 hours is a very long period of time but then again that's with next to nothing for air pressure to get a breathable air pressure.

Mars_B4_Moon · 2022-09-01 05:06:02

Very important start and it might be good idea to have as many Oxygen sources as possible

SpaceNut · 2022-09-01 22:04:14

The device is meant to scale up in size but with that it's still will need testing to ensure that we get performance for power used.

SpaceNut · 2023-06-29 22:54:35

A new try has done, much better at the conversion...

NASA Is One Step Closer To Terraforming Mars

While Perserverance's Mars Oxygen In Situ Resource Utilization Experiment (MOXIE) has previously managed to harvest oxygen on the Red Planet, this time it went even further by doubling its production level. In a move that MOXIE's principal investigator, Michael Hecht called "the riskiest run" that the NASA team has ever pulled off, the rover raked in somewhere around 12 grams of oxygen from Mars in just 58 minutes. Pushing themselves and Perseverance to the limit, the scientists are thrilled that they challenged their original beliefs.

another note

News of NASA's latest win on Mars comes just days after it was revealed that the agency has found a way to recycle pee and other bodily fluids (i.e. sweat) into water. Another giant leap forward, this technology could elongate the time of missions in space, allowing astronauts to go farther than ever before. And don't worry – the water is totally safe to drink with one spokesperson even saying that it's cleaner than the water we have on Earth.

Mars_B4_Moon · 2023-09-09 16:42:34

NASA's completes Oxygen-Generating Experiment MOXIE

https://www.spacedaily.com/reports/NASA … E_999.html

Since Perseverance landed on Mars in 2021, MOXIE has generated a total of 122 grams of oxygen - about what a small dog breathes in 10 hours. At its most efficient, MOXIE was able to produce 12 grams of oxygen an hour - twice as much as NASA's original goals for the instrument - at 98% purity or better. On its 16th run, on Aug. 7, the instrument made 9.8 grams of oxygen. MOXIE successfully completed all of its technical requirements and was operated at a variety of conditions throughout a full Mars year, allowing the instrument's developers to learn a great deal about the technology.

"We're proud to have supported a breakthrough technology like MOXIE that could turn local resources into useful products for future exploration missions," said Trudy Kortes, director of technology demonstrations, Space Technology Mission Directorate (STMD) at NASA Headquarters in Washington, which funds the MOXIE demonstration. "By proving this technology in real-world conditions, we've come one step closer to a future in which astronauts 'live off the land' on the Red Planet."

MOXIE produces molecular oxygen through an electrochemical process that separates one oxygen atom from each molecule of carbon dioxide pumped in from Mars' thin atmosphere. As these gases flow through the system, they're analyzed to check the purity and quantity of the oxygen produced.

SpaceNut · 2023-09-09 17:15:58

It's sort of doing it with a process of super heat and catalyst materials sort of like electrolysis or a fuel cell in reverse.

Mars_B4_Moon · 2024-01-05 09:00:25

MOXIE demonstrated how to create breathable air on the Martian surface.
https://cosmicchroniclesnews.com/2023/1 … n-on-mars/
It successfully produced oxygen on Mars for the first time on April 20, 2021, and has since demonstrated its capability to generate oxygen from the carbon dioxide present in the Red Planet’s atmosphere. MOXIE has achieved multiple runs, generating oxygen at different rates to validate its functionality and performance in the challenging Martian environment. These successful oxygen production runs mark a significant milestone in the development of technologies necessary for future human survival.

Elon Musk Criticizes Stagnant Space Exploration, Stating: 'Humanity Should Have A Moon Base, Cities On Mars And Be Out There Among The Stars'
https://finance.yahoo.com/news/elon-mus … 38307.html

some backup ideas because you can never have too much air?

Chemistry? ISS Oxygten Candle and SCOGs are used in submarines, on Commercial aircraft provide emergency oxygen to passengers.

2 NaClO3 → 2 NaCl + 3 O2
LiClO4 → LiCl + 2 O2

discussion Chemistry - Chemists - Chemicals
https://newmars.com/forums/viewtopic.php?id=10415

Trees, Plants, Algae, Photosynthesis like aquatic plants, algae also produce oxygen via photosynthesis.

Current experiments on algea, lichen etc.?
https://newmars.com/forums/viewtopic.php?id=236

Productive walking Baba Yaga Robot Trees.
https://newmars.com/forums/viewtopic.php?id=9563

Mass About 37.7 pounds (17.1 kilograms) on Earth
https://mars.nasa.gov/mars2020/spacecra … nts/moxie/
Weight 37.7 pounds on Earth, 14.14 pounds on Mars
Power 300 watts

SpaceNut · 2024-01-05 18:24:13

Yes, it will be good to have backups in lots of different forms as you have indicated.

SpaceNut · 2024-02-19 20:52:28

Orion has for a crew of 4 they need for 21 days just 90 kg of oxygen in three tanks (= 270kg), 30 kg of nitrogen for near normal air
With space suits give another 144 hours.

At 300 watts to get about 6 g to 12 g which a far cry for an hour runtime when we need roughly 600 g for a days' worth of breathing per crewman.

Thanks to Void we have another to make use of in "Mars Direct 3 is a Mars mission architecture developed by Miguel Gurrea" topic.
https://www.marspapers.org/paper/Gurrea_2021.pdf

Plus Mars direct was a 40mT payload
https://www.marspapers.org/paper/Zubrin_1991.pdf

A reuseable craft requires the means to make the fuel of choice.

SpaceNut · 2025-11-27 17:23:39

https://www.nasa.gov/space-technology-m … ent-moxie/

update:

The largest solid oxide electrolyzer (SOE) developed for Mars is the mission-scale SOXE stack by OxEon Energy, a 33x scaled-up version of the toaster-sized MOXIE device on NASA's Perseverance rover, designed to produce propellant for human return missions, though the MOXIE unit itself was the first SOE to operate on Mars, generating oxygen from CO2. On Earth, Bloom Energy's 4 MW Bloom Electrolyzer is the world's largest SOE system, stemming from that original NASA Mars technology.
For Mars Missions (Technology for Future Human Exploration):
MOXIE (Mars Oxygen ISRU Experiment): This small, toaster-sized SOE device on the Perseverance rover successfully demonstrated solid oxide electrolysis on Mars, producing oxygen from the thin CO2 atmosphere.
OxEon Mission-Scale SOXE: OxEon scaled up its MOXIE technology significantly (33x) for potential Mars crewed missions, aiming to produce large quantities of oxygen for propellant (Mars Ascent Vehicle) and life support, according to this TTU DSpace Repository document and OxEon Energy's website.
For Earth (Current Largest SOE):
4 MW Bloom Electrolyzer: Bloom Energy built the world's largest solid oxide system, operating at NASA's Ames Research Center, with roots in the original Mars technology to produce clean hydrogen for terrestrial decarbonization.
In summary, MOXIE was the first SOE on Mars, OxEon scaled it up for future large-scale Mars needs, and Bloom Energy created the largest SOE on Earth based on that heritage

Scale Up and Coupling of the MOXIE Solid Oxide Electrolyzer for Mission-Scale Lunar and Martian Applications

SpaceNut · 2025-12-21 15:52:49

Still waiting for updates but here is the test that was done on mars. MOXIE accomplishes this by sucking in Martian atmosphere, scrubbing out dust, and then compressing and heating it to almost 1,470°F (800°C). Inside the module, a solid oxide electrolyzer breaks down carbon dioxide molecules (CO₂) in to oxygen ions and carbon monoxide. The oxygen ions are recombined into O₂, quantified for purity, and discharged. The waste, carbon monoxide, is discharged back into the Martian atmosphere. Overall, MOXIE produced 122 grams of oxygen, enough for a small dog to breathe for 10 hours or a human for 4 hours. But it only produced 6 grams with a limitation of an hour, With hopes of getting to 14 grams.

Currently, a crew of four astronauts would require approximately 55,000 pounds (25 metric tons) of oxygen for rocket propellant, while only about one metric ton is needed for breathing over a full year on Mars.

update to get better runtime to output.

NASA's MOXIE experiment on the Perseverance rover produces oxygen by electrolyzing Martian CO2, with a typical run taking about 3.5 hours (2.5 hours warmup, 1 hour production) to generate roughly 6-10 grams per hour, enough for a small dog to breathe, exceeding initial goals by generating higher purity oxygen and scaling up production, proving technology for future human missions.
MOXIE Run Cycle Breakdown
Warmup: About 2.5 hours for the Solid Oxide Electrolyzer (SOXE) to reach ~800°C.
Production: Around 1 hour of active oxygen generation.
Total Cycle: Roughly 3.5 hours.
Production Output & Goals
Rate: 6-10 grams of oxygen per hour (g/h) in its standard runs, later reaching up to 12 g/h.
Purity: Achieved high purity (98% or better).
Total: Generated over 122 grams by its mission's end.
Analogy: 6 g/h is like a modest Earth tree; 100 minutes of oxygen is enough for one astronaut for a short time.
Key Achievements
Demonstrated oxygen production in various conditions (day/night, seasons).
Proved the viability of In-Situ Resource Utilization (ISRU) for human exploration.
Exceeded initial goals for production rate and purity, paving the way for scaled-up versions for future missions

Goal is continuous run not a cycled loop. So the above is not representing this information.

GW Johnson · 2025-12-21 16:16:03

Propellant manufacture is by far more hungry for high oxygen generation rates. The equipment to do this will inherently be large, and power-consumptive. There is no way around that ugly little fact of life.

I rather think that electrolyzing water purified from mined ice is the better choice for propellant manufacture, especially if the propellant is LOX-LH2. Your biggest energy expenditure will be for liquifying the gases. Although electrolysis might be a fairly close second, if the ~6% efficiency typical here obtains there.

It is possible to get LOX-LCH4 propellants by using both water and Martian CO2. But it's neither electrolysis nor the Moxie process. Just more big heavy, power-consumptive machinery to do it on a big scale.

Purifying water from likely-polluted ice is a thermal process after an initial filtering process. Either you distill it, or you freeze it. Sea water freezes to fresh water ice, enhancing the brine content in the sea water just below the ice cake. You could run it through 2 to 4 steps of that, and get most of the various salts out, possibly even including the perchlorates. But all the water you start with will reach the end as product; there will be significant concentrated brine waste. You can take advantage of the cold environment to do the freezing. Distillation would work just like it does here. You just need to supply a lot of heat energy. And again, not all the water you start with arrives as product. There will always be concentrated brine waste! It is a Second Law thing.

For the Martian CO2, the biggest problem is compression. Compressors there will look (and weigh) more like vacuum pumps, a lot of power-consumptive machinery for just a very small throughput stream. The 6 mbar atmospheric pressure is what forces that outcome. 10 mbar, no difference. Same problem: the local "air" is a 1st cousin to vacuum.

If you can slightly cool some sort of duct to a temperature below about -110 F, the CO2 will preferentially condense out first as a dry ice frost or snow in the duct. You would have to stop and recover it out of that duct, making this more of a batch process than any sort of continuous flow process. Be that as it may, pack the recovered dry ice tightly into a pressure container, and warm it above -110 F. It will be high-pressure CO2 gas in that container in a small amount of time, and for very little energy input compared to direct compressor-type compression. Once near 1+ atm pressure, your ordinary Earthly-type compressors and other machinery will work "right". But not until you "pre-compress" it to near 1 atm.

GW

SpaceNut · 2025-12-21 18:18:06

Rather than using the electrical power we could use the Krusty reactor heat to do the job.

The KRUSTY (Kilopower Reactor Using Stirling TechnologY) reactor operated at a target core temperature of around 800°C (1472°F), reaching up to 880°C during testing, to generate about 4-5.5 kW of thermal power for space applications, demonstrating efficient fission power at relatively high temperatures for long-duration missions.
Key Temperatures & Operations:
Design Goal: Achieve steady-state operation at ~800°C (4 kW thermal).
Peak Test Temperature: Reached up to 880°C (1616°F) during the full-power run.
Warm Criticals: Pre-test experiments heated the core to 200°C, 300°C, and 450°C to study reactivity.
Control: Temperatures were adjusted by moving control rods, allowing for standby heat or shutdown.
Significance:
Demonstrated the Kilopower system's ability to operate reliably at high temperatures, crucial for space power.
Validated nuclear codes and material performance for potential long-term use in space

I did this equation back in the 1 m water topic.

MOXIE converts Martian CO2 into oxygen (O2) and carbon monoxide (CO) using solid oxide electrolysis, where roughly 2 moles of CO2 yield
1 mole of O2, meaning for every ~44 grams of CO2 consumed, MOXIE produces ~32 grams of O2, though its actual output is ~6-10 grams O2/hour from ~55 grams CO2/hour, with CO as a byproduct, not just pure O2 output.
MOXIE's Process & Ratios: Input: MOXIE takes in Martian atmosphere (95% CO2).Reaction: It uses electrolysis to split CO2 into Carbon Monoxide (CO) and Oxygen (O).
Output: Oxygen gas (O2) is collected, and Carbon Monoxide (CO) is released as a byproduct.
Stoichiometry: The balanced equation is roughly \(2CO_{2}\rightarrow 2CO+O_{2}\) (simplified for mass flow).
Mass Conversion (Theoretical): Molar Mass of \(CO_{2}\approx 44\) g/molMolar Mass of \(O_{2}\approx 32\) g/molFor every 44g of CO2, you get 32g of O2 (and 28g of CO).
This means for every 1 gram of O2 produced, about 1.375 grams of CO2 are needed (44/32).
MOXIE's Actual Performance: MOXIE aims for 6 grams of O2 per hour using about 55 grams of CO2 per hour.
This 55g CO2/hour input yields ~6g O2/hour output, which is roughly a 9:1 mass ratio of CO2 in to O2 out, reflecting the byproduct CO and operational inefficiencies.
In summary, it's not a direct 1:1 mass conversion; a larger mass of CO2 is consumed to produce a smaller mass of pure oxygen, with the rest becoming carbon monoxide

One cubic meter of Mars \(\text{CO}_{2}\) (assuming the general Martian atmosphere which is predominantly \(\text{CO}_{2}\) gas) is approximately 19 grams (0.019 kg), though the exact value varies with location and season on Mars.

tahanson43206 · 2025-12-21 18:59:05

For SpaceNut ... please ask you AI friend to confirm this:

To the best of my knowledge there is only ONE experiment ever performed on Mars to produce Oxygen and the fuel Carbon Monoxide.

All the conversation we see in the NewMars forum is about hypothetical processes that might work.

Please ask your AI friend to confirm that there have been NO other experiments performed.

Why introduce other methods what that one works?

(th)

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#51 2021-10-19 17:49:49

Re: Moxie and only Moxie

#52 2022-03-12 18:28:29

Re: Moxie and only Moxie

#53 2022-04-20 05:51:41

Re: Moxie and only Moxie

#54 2022-04-20 06:12:50

Re: Moxie and only Moxie

#55 2022-04-20 17:39:30

Re: Moxie and only Moxie

#56 2022-08-31 20:22:26

Re: Moxie and only Moxie

#57 2022-09-01 05:06:02

Re: Moxie and only Moxie

#58 2022-09-01 22:04:14

Re: Moxie and only Moxie

#59 2023-06-29 22:54:35

Re: Moxie and only Moxie

#60 2023-09-09 16:42:34

Re: Moxie and only Moxie

#61 2023-09-09 17:15:58

Re: Moxie and only Moxie

#62 2024-01-05 09:00:25

Re: Moxie and only Moxie

#63 2024-01-05 18:24:13

Re: Moxie and only Moxie

#64 2024-02-19 20:52:28

Re: Moxie and only Moxie

#65 2025-11-27 17:23:39

Re: Moxie and only Moxie

#66 2025-12-21 15:52:49

Re: Moxie and only Moxie

#67 2025-12-21 16:16:03

Re: Moxie and only Moxie

#68 2025-12-21 18:18:06

Re: Moxie and only Moxie

#69 2025-12-21 18:59:05

Re: Moxie and only Moxie

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